Fluid-actuated percussive machine



Aug. 3l 1926.,

w. FQZIMMERMANN FLUID ACTUATED PERCUSSIVE MACHINE INI/ENTOR. Zim f 1 61111101212 q/ )fl/5 ATTNEY,

Filed June' 4:,

Patented ug. 3l, 1926.

UNITED STATES PATENT oFFlce.

WILLIAM FRANK ZIMMERMANN, F WAYERLY, NEW YORK, ASSIGNOR TO INGERSOLL- RAND COMPANY, OF JERSEY CITY, NEW JERSEY, A CORPORATION OF NEW JER- SEY.

FLID-ACTU'ATED PERCUSSIVE MACHINE.

Application filed June 4, I1925. Serial, No. 34.775.l

This invention relates to fluid actuated percussive tools or machines, but more particularly to a hand held machine in which the piston reciprocates in the cylinder and having the forward extension or iston rod C extending through the gland referably havin acking materlal E. l 1|: foris controlled by a fluid actuated distributing valve. In the present embodiment of the invention the piston is provided with a shank or piston rod so that the machine is of the piston drill type and is particularly useful as a sand rammer.

The objects of the invention are to improve the construction and operation of the automatic distributing valve which in this instance controls only the inlet of live pressure fluid to the cylinder. A free exhaust in the side of the cylinder is controlled only by the piston and the valve itself is an improvement on the so called type of current valve in which the flow or current of pressure fluid in conjunction with the drop of pressure beneath' one end of the valve and compression of fluid by the pistonexerted a ainst the other end of the valve causes t e valve to o crate.

ln accordance wit this improved construction, the valve is light, consumes a small amount of space, and may be conveniently located rearwardly of the cylinder in a valve box in line with the cylinder. v The invention is illustrated in one of its preferred forms in the accompanying drawin, in whichzv igure l is a longitudinal sectional elevation of so much ofy a sand rammer as will serve to make the invention clear,

Figure 2 is a similar view with the piston in a diderent position,

Figure 3 is a detail transverse sectional view taken en the line r-B of Figure l looking in the direction of the arrows, and

Figure 4 is adetail side elevation of the valve.

Referrin to the drawings, the cylinder A is provide with the reciprocating piston B .Ward end o t e piston extension C is shown broken away, but it is to be understood that this forward extension or piston rod may be provided with any suitab e tool or implement for the. purposes desired, as for in- `stance, the pieton rod may be equipped with a sand raing head.

The back head F having the inlet G for live pressure Huid may be secured to the cylinder A. in any suitable' manner, and within the back head rearwardly of the cylinder andv in line therewith 1s located a valve box containing the valve H.

vAs shown the valvebfox comprising the front section or block J and the body K, between which the valve H is located in a shallow circular recess L in the body K, is a convenient construction.

The valve H is a comparatively thin plate valve in the form of an oscillating circular disk uniformly tapered from its m'edian diameter O towards the periphery at each side so that the valve oscillates about its 70 center axis. The valve disk is preferably cut on the cords of thel circle at opposite sides to form the straight edges P and Q and thus permit the live pressure fluid to pass over the said straight edges of the 75 valve and through the clearance space thus provided to the cylinder. rlihe valve is preferably guided in a ysuitable manner as by means of the pins R extending through the. valve with slight but suiicient clearance in S0 the valve to permit the valvevto rock free-I ly. Suflicient clearance is also provided between the periphery of Vthe valve and the valve box to prevent binding and permit free oscillation.

The body K of the'valve box is provided with the inlet passages S and the block or valve box section J is provided with the inlet ports T and U controlled only by the valve. The inlet port T leads to the rear t0 end of the, cylinder while the inlet port lU communicates with the inlet passage V leading to the inlet port W at the forward end of the cylinder. An exhaust passage X in the cylinder communicates with the atmospheric exhaust port Y at one end and with the exhaust port Z located centrally of the cylinder. iis shown there may be two exhaust. ports Z communicating with the exhaust passage X.

ln the operation of the device, let it be assumed that the piston is at the rear end of the cylinder as indicated in Figure l with the valve H also in the position indicated, so that the live pressure fluid entering at l0 the inlet `G holds the end Q of the valve down over the inlet port U, the under side of the valve at this end being at atmospheric pressure through the c linder and exhaust port Y. Live pressure uid passes over the El@ end P of the valve and through the inlet port T to the rear end of the cylinder to drive the piston B forwardly.

ln Figure 2 the piston is shown substantially at the end of its forward -stroke and is returning on its rearward stroke since the valve H is rocked to its opposite position closing the inlet port T and opening the inlet port U to the forward end of the cylinder. As the piston B uncovers the rearward exhaust port Z in its forward stroke, the pressure beneath the end P of the valve is dropped underneath the entire surface of one half of the valve so that the live pressure fluid on top of the valve tending to flow over the valve and the compression pressure beneath the opposite end of the valve actuates the valve and closes the inlet port T causing the valve to open the inlet port U. From this point the cycle is repeated as the piston reciprocates.

I claim l. A fluid actuated percussive machine, comprising a cylinder and reciprocating piston, a free exhaust port located centrally of the cylinder and controlled only by the piston, a valve box. having a seat portion and a shallow circular recess located at the rear end of the cylinder and in line therewith, a plate valve in the form of a thin mesma flat, oscillating circular disk in said shallow valve box recess, said valve disk being uniformlytapered from its median diameter towards the periphery at each side, and bearing on the seat portion of the valve box along said median diameter, and inlet ports in the seat portion of the valve box for the ends of the cylinder controlled only by the valve.

2. A fluid actuated percussive machine, comprising a cylinder and reciprocating piston, a free exhaust port located centrally of the cylinder and controlled only by the piston, a valve box having a seat portion and a shallow circular recess located at the rear end of the cylinder and in line therewith, a plate valve in the form of a thin, flat oscillating circular disk seated in said shallow valve box recess, said valve disk havingl clearance at opposite edge portions and being uniformly tapered from its Inedian diameter towards said opposite edge portions, land inlet ports in the seat portion of said valve box for the ends of the cylinder controlled only. by said opposite edge portions of the valve.

In testimony whereof I have signed this specification.

WLLIAM yFRANK ZIMMERMANN. 

